The present invention generally relates to non-volatile switching and memory devices. More particularly, the present invention in some embodiments provides a structure and a method of forming resistive switching non-volatile memory devices using a metal oxide as a switching element.
Memory devices are usually transistor based. Current memory devices shrink is primarily driven by a scale down of the transistor. Recent developments in other memory device structures, such as ferroelectric RAM (Fe RAM), magneto-resistive RAM (MRAM), organic RAM (ORAM), and phase change RAM (PCRAM) are limited by a lack of one or more attributes to high density and high speed memory devices. For example, Fe-RAM and MRAM are fast switching and having high programming endurance, they are however, not compatible to CMOS processing. The device size is too large and limited in further device size shrink. PCRAM uses Joule heating for resistivity switching and therefore incurs an increase in power consumption. Additionally, PCRAM is also limited by uniformity in phase change control when the device is scaled down. ORAM suffers from incompatibility with present CMOS processing as well as device reliability and low device yield.
From the above, scalable memory devices and device structures compatible with present CMOS process technology are desirable.